So according to the label that 1.1 oz. in 1 Gal. of water is for 1000 sq.ft. You need to mark out 1000 Sq. ft. in your paved driveway and figure out how much water in your sprayer that take's. You need to adjust to get it to 1 Gal. and go from there. I'd be careful with that dishwashing soap. That's a quick way to make a big mess. Good luck.